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tscroll.c revision 1.4 
      1 /*	$NetBSD: tscroll.c,v 1.4 1997/07/22 07:37:08 mikel Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)tscroll.c	8.4 (Berkeley) 7/27/94";
     40 #else
     41 __RCSID("$NetBSD: tscroll.c,v 1.4 1997/07/22 07:37:08 mikel Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 #include "curses.h"
     46 
     47 #define	MAXRETURNSIZE	64
     48 
     49 /*
     50  * Routine to perform scrolling.  Derived from tgoto.c in tercamp(3)
     51  * library.  Cap is a string containing printf type escapes to allow
     52  * scrolling.  The following escapes are defined for substituting n:
     53  *
     54  *	%d	as in printf
     55  *	%2	like %2d
     56  *	%3	like %3d
     57  *	%.	gives %c hacking special case characters
     58  *	%+x	like %c but adding x first
     59  *
     60  *	The codes below affect the state but don't use up a value.
     61  *
     62  *	%>xy	if value > x add y
     63  *	%i	increments n
     64  *	%%	gives %
     65  *	%B	BCD (2 decimal digits encoded in one byte)
     66  *	%D	Delta Data (backwards bcd)
     67  *
     68  * all other characters are ``self-inserting''.
     69  */
     70 char *
     71 __tscroll(cap, n1, n2)
     72 	const char *cap;
     73 	int n1, n2;
     74 {
     75 	static char result[MAXRETURNSIZE];
     76 	int c, n;
     77 	char *dp;
     78 
     79 	if (cap == NULL)
     80 		goto err;
     81 	for (n = n1, dp = result; (c = *cap++) != '\0';) {
     82 		if (c != '%') {
     83 			*dp++ = c;
     84 			continue;
     85 		}
     86 		switch (c = *cap++) {
     87 		case 'n':
     88 			n ^= 0140;
     89 			continue;
     90 		case 'd':
     91 			if (n < 10)
     92 				goto one;
     93 			if (n < 100)
     94 				goto two;
     95 			/* FALLTHROUGH */
     96 		case '3':
     97 			*dp++ = (n / 100) | '0';
     98 			n %= 100;
     99 			/* FALLTHROUGH */
    100 		case '2':
    101 two:			*dp++ = n / 10 | '0';
    102 one:			*dp++ = n % 10 | '0';
    103 			n = n2;
    104 			continue;
    105 		case '>':
    106 			if (n > *cap++)
    107 				n += *cap++;
    108 			else
    109 				cap++;
    110 			continue;
    111 		case '+':
    112 			n += *cap++;
    113 			/* FALLTHROUGH */
    114 		case '.':
    115 			*dp++ = n;
    116 			continue;
    117 		case 'i':
    118 			n++;
    119 			continue;
    120 		case '%':
    121 			*dp++ = c;
    122 			continue;
    123 		case 'B':
    124 			n = (n / 10 << 4) + n % 10;
    125 			continue;
    126 		case 'D':
    127 			n = n - 2 * (n % 16);
    128 			continue;
    129 		/*
    130 		 * XXX
    131 		 * System V terminfo files have lots of extra gunk.
    132 		 * The only one we've seen in scrolling strings is
    133 		 * %pN, and it seems to work okay if we ignore it.
    134 		 */
    135 		case 'p':
    136 			++cap;
    137 			continue;
    138 		default:
    139 			goto err;
    140 		}
    141 	}
    142 	*dp = '\0';
    143 	return (result);
    144 
    145 err:	return("curses: __tscroll failed");
    146 }
    147